One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(25,26)(27,32)(28,29)(30,33)(31,34)(35,39)(36,37)(38,40)(1,3,5,8)(2,6,4,7)(9,10,14,15)(11,17,20,16)(12,21,23,13)(18,24,22,19)(25,26,31,34)(27,32,28,29)(30,33,38,40)(35,39,36,37)(2,4)(6,7)(10,15)(13,21)(16,17)(19,24)(25,27,31,28)(26,32,34,29)(30,36,38,35)(33,37,40,39)(1,3,5,8)(2,6,4,7)(9,11,14,20)(10,16,15,17)(12,22,23,18)(13,19,21,24)(25,28,31,27)(26,32,34,29)(30,36,38,35)(33,39,40,37)(1,3)(2,6)(4,7)(5,8)(9,12)(10,13)(11,18)(14,23)(15,21)(16,24)(17,19)(20,22)(25,29,31,32)(26,28,34,27)(30,37,38,39)(33,36,40,35)(1,4,5,2)(3,7,8,6)(9,13)(10,12)(11,19)(14,21)(15,23)(16,22)(17,18)(20,24)(25,30,31,38)(26,33,34,40)(27,35,28,36)(29,37,32,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.